Add missing CFLAGS/LIBS in the src/configuration/Makefile.am
Add missing CFLAGS/LIBS in the src/configuration/Makefile.am

If the libical is installed in a different prefix than the one shared
by other CFLAGS, then the test compilation breaks due to failed search
for the <libical/ical.h> include file.

GNOME/evolution-ews,GNOME/evolution-ews